The Olympic trials are starting in earnest, with three -- triathlon, women's marathon and flatwater kayak -- scheduled this weekend. Here's a look at key U.S. trials for this summer's Beijing Games:

Trials Date Site

Wrestling June 13-15 Las Vegas

Gymnastics June 19-22 Philadelphia

Track and field June 27-July 6 Eugene, Ore.

Swimming June 29-July 6 Omaha